Paperback of the week

Taking the high road

The Ancestor's Tale: A Pilgrimage to the Dawn of Lifeby Richard DawkinsPhoenix £9.99, pp416

For a man variously dubbed Darwin's rottweiler and the world heavyweight atheism champion, Richard Dawkins can't seem to get the divine out of his soul. On a recent edition of Radio 4's With Great Pleasure, the literary equivalent of Desert Island Discs, he selected a passage from Ecclesiastes. Among the titles of his books are River Out of Eden and A Devil's Chaplain. Now comes The Ancestor's Tale: A Pilgrimage to the Dawn of Life, which again annexes the language of religion because 'pilgrimage is an apt way to think about the journey to the past'. Dawkins tells the story of evolution backwards, starting with humankind and ending in primordial slime.

Following the structure of Chaucer's The Canterbury Tales, we stop off at evolutionary crossroads along the way, hearing the tales of our wondrously weird ancestors as they join the 'pilgrimage' to the past.

It's an enticing metaphor which doesn't quite come off. Dawkins rightly rejected as twee the idea of each animal or plant telling its own tale in the first person singular, but finds it impossible to keep the narrative coherently marching in one direction while also stuffing in a breathtaking range of scientific sources, glimpses of his childhood in Malawi, incongruous swipes at Bush and Blair and, not least, four billion years' worth of complexity and mystery. Inevitably, our pilgrims don't stick to the high road but go ambling sideways with the unruly gait of drunkards.

In anyone's else hands, such epoch hopping would be unpalatably hard work, but Dawkins below his very best is still more readable than almost anyone else, a master of liquid-clear prose and revelatory pearls of insight. For particular genes, for instance, he notes: 'You are more closely related to some chimpanzees than to some humans.'

As intellectual workouts go, this is a mind-expanding marathon, even if you're not always sure which way to run.